Applicator and method for making a printing form

ABSTRACT

A carrier foil having a layer of microcapsules containing a printing lacquer consisting of a resin and a solvent. When the carrier foil is superimposed on a printing foil, and the microcapsules broken by the impact of a type or melted by radiation along a desired outline, the lacquer is applied to the printing foil along the desired outline, and adheres to the printing foil when the same is separated from the carrier foil and from the remainder of the layer.

United States Patent 1191 Ritzerfeld 1 Dec. 17, 1974 [54] APPLICATOR ANDMETHOD FOR MAKING 3,470,059 9/1969 Jonnes 161/119 A PRINTING FORM3,476,937 1 H1969 Vrancken l l7/36.1 3,484,318 12/1969 Neufeld et a1. 1161/160 6] n r: Gerhard Ritzerfeld, 1000 Berlin 33 3,505,955 4/1970Ritzerfeld 117/361 (Dahlem), Germany 3,598,581 8/1971 Reinis 117/37 R3,697,323 10/1972 Brown, Jr. et al. ll7/36.1

[22] Wed: 1971 3,728,210 4/1973 Piron 161/162 Appl. No.: 182,983

Foreign Application Priority Data Sept. 25, 1970 Germany 2049019 US. Cll17/36.l, 117/37 R, 161/160, 161/162 Int. Cl. B41m 5/10, C04b 35/00Field of Search 117/37 R, 36.1; 161/160, 161/162, 168

References Cited UNITED STATES PATENTS 5/1960 Tien 117/36.1 l/l967Plambeck, .lr. 5/1967 Eichel ll7/36.l

Primary Examiner-William J. Van Balen Attorney, Agent, or Firm-MichaelS. Striker 57 ABSTRACT A carrier foil having a layer of microcapsulescontaining a printing lacquer consisting of a resin and a solvent. Whenthe carrier foil is superimposed on a printing foil, and themicrocapsules broken by the impact of a type or melted by radiationalong a desired outline, the lacquer is applied to the printing foilalong the desired outline, and adheres to the printing foil when thesame is separated from the carrier foil and from the remainder of thelayer.

10 Claims, 6 Drawing Figures APPLICATOR AND METHOD FOR MAKING A PRINTINGFORM BACKGROUND OF THE INVENTION The present invention relates to amethod of making a printable image on a lithographic printing foilconsisting of metal, preferably aluminum, paper, or a syntheticmaterial, or consisting of several of the aboveenumerated substances,which may form different superimposed foils. The method is carried outby using an applicator sheet, according to the invention, which includesa carrier foil, and a layer of microcapsules bonded to the carrier foil.

In lithographic printing, according to the prior art, a printable imageis formed on the printing foil of a fatty substance, or lacquer isapplied to the printing foil by a pen or brush. However, fattysubstances forming an image, for example of a character, are inferior toa lacquer in forming an adherent base, particularly it is not possibleto add to the moistening water, anti-toner substances, since the samecreep under the fatty base. When lacquers are used for making a printingfoil, it is not possible to produce the desired outline by the types ofa typewriter, or by applying infrared heat along the desired outline.

SUMMARY 'OF THE INVENTION It is one object of the invention to overcomethe disadvantages of prior-art methods of making a printing foil, and toprovide a method which permits the application of any desired substance,particularly lacquer, to the printing foil along a desired outline.

Another object of the invention is to provide a method permitting theuse of a typewriter for forming an image consisting of lacquer on aprinting foil.

Another object of the invention is to provide a method permitting theuse of infrared light for forming an image consisting of a lacquer on aprinting foil.

Another object of the invention is to provide a printing foil with aprintable outline of an image having great adhesive capacity, permittingthe use of moistening liquids, and having great tone stability duringprinting.

Another object of the invention is to make possible the requiredanti-toner stability for direct lithographic printing in which theprinting face of the printing foil is dried by the paper which is beingimprinted.

Another object of the invention is to make a printing foil particularlysuited for printing operation in which the printing cylinder isfrequently stopped after making a comparatively small number of copies,so that the printing form must be absolutely tone stable after one ortwo revolutions of the printing cylinder.

Another object of the invention is to provide an applicator sheet forcarrying outthe method of the inventron.

Another object of the invention is an applicator sheet comprising acarrier foil, and a layer of microcapsules thereon, preferablycontaining a lacquer, and adapted to be opened along the outline of adesired image to be printed.

With these objects in view, a method according to the invention ofmaking a printing form, uses a carrier foil having on the front face alayer of microcapsules containing a substance, such as a lacquer. Thecarrier foil is superimposed on a printing foil so that the layer ofcapsules is in contact with the front face of the printing foil. Energyis applied to the rear face of one of the foils along the outline of animage so as to open the microcapsules of the layer along the outlinewhereby the substance released by the opened microcapsules adheres tothe front face of the printing foil along the outline.

The printing foil with the adhering substance and the carrier foil withthe remaining portions of the layer, are separated from each other sothat the substance adhering to the printing foil forms a printableoutline of the desired image.

In accordance with the invention, the capsules contain a fast dryingoleophilic lacquer consisting of a resin and a solvent.

Energy can be applied along the outline to be printed by the impact of amoving type on the respective foil so that microcapsules are brokenalong the character outline by the impacts of the type.

Energy can also be applied by heating the outline of the image and theremaining portions of the carrier foil differently, so that the capsulesforming the image melt and open. After the evaporation of the solvent,the resin forms a very durable base to which the lithographic printingink reliably adheres.

The method of the invention can be carried out with different printingfoils, for example electrolytically roughened aluminum foils, or brushedaluminum foils. A paper backing may be adhesively attached to thealuminum printing foil, and coated with a water-resistant lacquer.Barite paper, or other lithographic paper foils,

. may also be used as printing foils. Acetate foils, or

a lacquer having at the temperature of 20 Centigrade,

a viscosity between 45 cP and 48 0F.

Preferably the lacquer is a mixture of a copolymerisate with a solvent,such as toluol and xylol.

EXAMPLE 1 22 parts by weight of a copolymerisate consisting ofvinylchloride and vinylisobutylether in a ratio of :25 are mixed with 78parts by weight of toluol.

EXAMPLE 2 21 parts by weight of a copolymerisate consisting ofvinylchloride and vinylisobutylether in a ratio of 75:25 are mixed with79 parts by weight of xylol.

It is preferred to form the layer on the carrier foil of microcapsuleshaving a diameter between 20 micron and 50 micron. The layer isadhesively attached to the carrier sheet.

The novel features'which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following de scription of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a schematic side viewillustrating the use of a typewriter for making a mirror-reversedprintable image on a printing form for direct lithographic printing;

- 'FIG. 2 is a schematic side view illustrating the applicator sheetandthe printing foil of FIG. 1 after separation of the printing formfrom the applicator sheet;

FIGS. 3 and 4 are schematic side views corresponding to FIGS. 1 and 2,but illustrating the making of an offset printing foil with a trueimage; and

FIGS. and 6 are schematic side views illustrating a modified methodusing radiation for making a printing form.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawing, a carrier foil1 has a front face to which a layer 2 consisting of microcapsules isadhesively bonded. A printing foil 3 is used. The type bar 5 of atypewriter has a type 4 with a character whose outline is to berepresented by the finished printing form. In the method of FIGS. 5 and6, an infrared lamp 8 is used together with a transparent sheet, towhich heatabsorbent material 7 forming the outline-of the desired imageis attached.

According to the method as shown in FIGS. 1 and 2, the layer 2 ofcapsules containing the lacquer is superimposed on the front face of aprinting foil 3. The type 4 is moved against the rear face of printingfoil 3, and the impact of the type causes breaking of the microcapsulesof layer 2 along the outline of the respective character. The broken andopened microcapsules apply lacquer portions to the front face of theprinting foil 3, forming with the same a printing form when printingfoil 3 is separated from carrier foil I with the remainder of the layer2. The image 2a is a mirror-reversed image.

In the method shown in FIGS. 3 and 4, the type bar 5 with type 4 isplaced at the rear face of the carrier 1 of the layer 2, and the impactalong the outline of the character of type 4, breaks capsules along thisoutline, so that lacquer adheres at 2a to the printing foil 3,formingwith the same a printing form after separation of the carriersheet I with the remainder oflayer 2 from the printing form 3,2 a.

In the methods of FIGS. 5 and 6, a printing foil 3 is superimposed onthe layer 2 which adheres to the carrier sheet 1. A transparent sheet 6with heat-absorbing material 7 arranged in accordance with the desiredoutline. is superimposed on the rear face of carrier foil 1. Infraredlight applied by lamp 8 passes through the transparent sheet, and isparticularly absorbed by the heat-absorbing, image-forming material 7,so that microcapsules of layer 2 melt and open in'the pattern of theheat-absorbing material 7, so that lacquer adheres in the same patternat 2a to the printing foil 3. When the printing form 3,2 a is separatedfrom the carrier sheet I with the remainder of layer 2, the printingfoil 3 carries a mirror-reversed image formed of the lacquer portions20. If a true image is to be made on the printing form, theheat-absorbent material 7 is applied to the rear face of the transparentsheet 6 which directly abuts It will be understood that each of theelements described above, or two or more together, may also find auseful application in other types of methods of making a printing formdiffering from the types described above.

While the invention has been illustrated and described as embodied in amethod of making a printing form by means of an applicator sheetconsisting of a carrier foil and of a bonded layer of microcapsulescontaining a lacquer, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

The layer 2 has a thickness from about 20 to about 400 microns.

Typical monomers which may be polymerized in the form of capsules by theprocess described in the US. Pat. Nos. 2,800,457 and 2,800,458 toGreeniinclude ethylacrylate, methylacrylate, methylmethacrylate,ethylmethacrylate, vinyl acetate, styrene and mixtures thereof.

The adhesive by which the layer 2 is bonded to the carrier foil 1 maycomprise resinous acid, casein, a colloidal material, or a syntheticresin dispersion, or a combination of all or some of such substances.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

I claim:

l. A method of making a printing form, comprising the steps of providinga printing sheet having a face on which a printable outline of an imageis to be formed; providing a carrier sheet having a surface providedwith a layer, said layer including microcapsules containing a fastdrying oleophilic lacquer comprising a mixture of at least one resin andat least one liquid solvent which is to be transferred at least in partto said face to form said outline contacting said layer with said face;releasing said lacquer from at least some of said microcapsules bytransmitting energy to regions of said layer corresponding to saidoutline so that the released lacquer contacts said face along saidoutlinelhereby enabling an adherent coating to be formed on said facealong said outline; and separating said sheets; whereby a printing formhaving said outline is obtained.

2. A method as defined in claim 1, wherein said energy is transmittedfrom said printing sheet to said layer so that said lacquer forms a trueoutline of said image on said printing form.

3. A method as defined in claim 1, wherein said energy is transmittedfrom said carrier sheet to said layer so that said lacquer forms amirror reversed outline of said image on said printing form.

4. A method as defined in claim 1, wherein said resin comprises acopolymer of vinylchloride and vinylisobutylether, said solvent beingselected from the group consisting of toluol and xylol.

5. A method as defined in claim 1, said outline being formed by lines ofpredetermined thickness, and said microcapsules being of substantiallythe same diameter; and wherein said diameter is smaller than saidthickness.

6. A method as defined in claim 5, wherein said diameter is betweensubstantially and 50 microns.

7. A method as defined in claim 1, wherein said lacquer has a viscositybetween substantially 45 and 48 cP at a temperature of 20C.

8. A method as defined in claim 1, wherein said step of releasing saidlacquer comprises breaking the micro- 6 capsules in said regions bytransmitting impact energy thereto.

9. A method as defined in claim 1, wherein said step of releasing saidlacquer comprises opening the microcapsules in said regions bypreferentially heating the same.

10. A method as defined in claim 9, wherein said energy is transmittedfrom said carrier sheet to said layer so that said lacquer forms amirror reversed outline of said image on said printing form.

1. A METHOD OF MAKING A PRINTING FORM, COMPRISING THE STEPS OF PROVIDINGA PRINTING SHEET HAVING A FACE ON WHICH A PRINTABLE OUTLINE OF AN IMAGEIS TO BE FORMED; PROVIDING A CARRIER SHEET HAVING A SURFACE PROVIDEDWITH A LAYER, SAID LAYER INCLUDING MICROCAPSULES CONTAINING A FASTDRYING OLEPHILIC LACQUER COMPRISJNING A MIXTURE OF AT LEAST ONE RESINAND AT LEAST ONE LIQUID SOLVENT WHICH IS TO BE TRANSFERRED AT LEAST INPART TO SAID FACE TO FOM SAID OUTLINE, SAID LACQUER INCLUDING A MIXTUREOF AT LEAST ONE THERMOPLASTIC RESIN AND AT LEAST ONE LIQUID SOLVENTCONTACTING SAID LAYER WITH SAID FACE; RELEASING SAID LACQUER FROM ATLEAST ONE TSOME OF SAID MICROCAPSULES BY TRANSMITTING ENERGY TO REGIONSOF SAID LAYER CORRESPONDING TO SAID OUTLINE SO THAT THE RELEASED LACQUERCONTACTS SAID FACE ALONG SAID OUTLINE THEREBY ENABLING AN ADHERENTCOATING TO BE FORMED ON SAID FACE ALONG SAID OUTLINE; AND SEPARATINGSAID SHEETS; WHEREBY A PRINTING FORM HAVING SAID OUTLINE IS OBTAINED. 2.A method as defined in claim 1, wherein said energy is transmitted fromsaid printing sheet to said layer so that said lacquer forms a trueoutline of said image on said printing form.
 3. A method as defined inclaim 1, wherein said energy is transmitted from said carrier sheet tosaid layer so that said lacquer forms a mirror reversed outline of saidimage on said printing form.
 4. A method as defined in claim 1, whereinsaid resin comprises a copolymer of vinylchloride andvinylisobutylether, said solvent being selected from the groupconsisting of toluol and xylol.
 5. A method as defined in claim 1, saidoutline being formed by lines of predetermined thickness, and saidmicrocapsules being of substantially the same diameter; and wherein saiddiameter is smaller than said thickness.
 6. A method as defined in claim5, wherein said diameter is between substantially 20 and 50 microns. 7.A method as defined in claim 1, wherein said lacquer has a viscositybetween substantially 45 and 48 cP at a temperature of 20*C.
 8. A methodas defined in claim 1, wherein said step of releasing said lacquercomprises breaking the microcapsules in said regions by transmittingimpact energy thereto.
 9. A method as defined in claim 1, wherein saidstep of releasing said lacquer comprises opening the microcapsules insaid regions by preferentially heating the same.
 10. A method as definedin claim 9, wherein said energy is transmitted from said carrier sheetto said layer so that said lacquer forms a mirror reversed outline ofsaid image on said printing form.